jose/lib/jwe/generate_cek.js
2019-01-26 14:24:12 +01:00

22 lines
540 B
JavaScript

const { randomBytes, createSecretKey } = require('crypto')
const OctKey = require('../jwk/key/oct')
const KEYLENGTHS = {
'A128CBC-HS256': 256 / 8,
'A192CBC-HS384': 384 / 8,
'A256CBC-HS512': 512 / 8,
'A128GCM': 128 / 8,
'A192GCM': 192 / 8,
'A256GCM': 256 / 8
}
module.exports = (alg) => {
const byteLength = KEYLENGTHS[alg]
if (byteLength === undefined) {
throw new TypeError('unsupported intended content encryption key alg')
}
return new OctKey(createSecretKey(randomBytes(byteLength)), { use: 'enc', alg })
}